Timing device



P. A. COFFMAN, JR

TIMING DEVICE Dec. 5, 1944,

Filed July 31, 1942 2 Sheets-$heet 1 O O f llllI-Il'I-l'l SINGLE POLE DOUBLE Tl/ROW SWITCHES ($49.3-

CONTROLLED cmcu/r INVENTOR PAUL A. COFFMAN JR.

BY i F ATTORBfY Dec. 5, 1944.

P. A. COFFMAN, JR

TIMING DEVICE Filed July 31, 1942 2 Sheets-Sheet 2 Q%,(/P 4 ATTORNEY INVENTOR PAUL A. coFrMAN JR.

m w m Patented Dec. 5, 1944 TIlWING DEVICE Paul'A. vCoffman, Jr., Kansas City, Mo., assignor to Omega Machine Company, Kansas City, Mo., a corporation of Missouri Application J My 31, 1942, Serial No. 453,089

7 Claims;

My, invention. relates. to. timing. devices, and more particularly to. devices. for controlling the timeinterval that a. circuit, ,or circuits, are en.- ergized relative to thetime interval. that such circuit, or circuits, arede-energized It is a. purpose of. my invention to provide. a timing device of the above mentioned character that is simple and cheaprin construction and at thesame time is. accurate inv operation and is capable. of accurate adjustment between such limitstliat the circuit .controlledbythe timing device canbe either open..or closed from 100% tic-% of the total time in any time interval.

My invention is particularly adapted for use in connection with the. controlotindustrial operations, to determine the percentage of the total time duringv any given time period that adevice will bein operation. In-thismanner the timing device. canbeused to accurately control the rate of operation of such devices as feeding devices, and can alsoube usedtocontroltemperatures. and various other varying. factors in which the operation ofa heating element, a mo- ,.tor, or other. electrically controlled or actuated means is operated in proportion to the lengthof canbeused generally for any-purpose where the time intervaldurin which acircuit is to be in operation or not in operation, i of importance. The timetinterval during. which a cycle of operations takes. place. canbemade. very short or very long,.as.may be found desirable. The de vice. can be so operatedrthat the cycle of operations'can be repeated a plurality of times. per second, a plurality of times per minute, or per. hour, or asinfrequently as once. perday, should this be found'desirable. However, the device is particularly adapted for. use where thetime interval for each cycle is relatively short, as the device is particularly-adaptable for such use, due to the fact that" it is capable of such accurate operation as topermit of such use without any appreciable error" in the results produced'thereby.

It is a particular purpose of my invention to provide in combination with an operating Circuit and an electrical supply line, means for controlling the time intervals over which the 'cir cuit is connected with and disconnected from the supply line, comprising a plurality ofsWitches and means for actuating these switches, comprising a member rotating at a constant speed, and means for adjusting thev position prone. switch relative to another thereof, whereby the time intervals are controlled.

More particularly my inventioncomprises a cam driven. at a, constantrate of speed, whichis provided with high and low portion andswitch operating members engaged withthesurface, of the cam for controlling the switches, wherebythe circuits are controlled to determine the time in-. tervals referred, to, one of saidswitches being mounted in fixed positionso that'the switch operatin member associated therewith will be. in a predetermined station in thetr ivel of the cam around its axis of rotation, andanother of said switchesbeing mounted for adjustment in an are about the axisof rotation of said cam so that the switch operating member. associated therewith will be adjustable-to vary the station thereof relative to the cam. and relativeto,thepreviously referred toswitch... I

My invention specifically comprises means for controlling the circuit so aseto. control the time intervals during which the. same-is connected with a source. of electricalenergy and disconnected fromsaidsource of electrical energy, comprising a cam and a switch mounted, for adjustment about the axis ofv rotation of .thecam, so

that the operating member for controlling the position of said switch acted on .by the cam will assume difierent positions about the axis of rotation of the cam, and mean for adjusting the position of said adjustable switch, including means for, indicating the position; to-wln'chthe switch has been adjusted. Said means specifically comprises an arm mounted for rotation about the axis of rotation of the-cam havin the switch and its operating means mounted thereon, and meansfor swinging said arm about said axis as a center through an are which is, preferably, and operating means therefor including a dial indicating the position of the arm on an appropriate scale, which is, preferably, calibrated in hundredths to indicate percentages;

In the preferred embodiment of myinvention a pair of switches is provided, which switches are included in a controlled circuit in such a manner that when said switches are in a corresponding position relative to each other, the controlled circult is disconected from the supply circuit, and when said switches are in an opposed position relative to each other, the controlledcircuit is connected with the supply circuit, and the switches are provided with actuating means including the aforementioned cam and switching means that are so arranged that the same can be adjusted, so that the operating members thereof are in axial alignment with each other transversely of the cam and thus in engagement with the same part of the cam to be actuated thereby, so as to always have corresponding positions, whereby the controlled circuit will be continuously disconnected from the supply circuit, or can be positioned so as to be diametrically opposite each other, which would result in the switches always having opposed positions, resulting in'the controlled circuit being continuously connected with the supply circuit, or the adjustable switching means can be moved to anyposition between the two positions, so as to control the period of time during which the switch operating members of the two switches are on the same portion or a different portion of the cam, to determine the length of time during any single rotation of the cam that the switches are in a corresponding or opposed position.

Other objects and advantages of my invention will appear as the description of the drawings proceeds. I desire to have it understood, however, that I do not intend to limit myself to the particular details shown or described. except as defined in the claims.

In the drawings:

Fig. 1 is a top plan view of my improved timing device.

Fig. 2 is a front elevational view thereof.

Fig. 3 is a diagram of the circuit employed in my improved timing device.

Fig. 4 is a vertical sectional view through the switch adjusting means and cam, with the switches, wiring and driving mechanism for the cam omitted, certain parts being in elevation.

Fig. 5 is a fragmentary view showing the cam and the switches cooperating therewith in elevation, and the driving pin for the cam in section, the view being taken substantially on the line 55 of Fig. 1, and showing the switches in the position shown in Fig. 1.

Fig. 6 is a diagrammatic view, similar to Fig. 5.

showing the switches in a relative position such thatthe controlled circuit will be constantly open, or de-energized, and

Fig. 7 is a similar view to Fig. 6, showing the switches in a position in which the controlled circuit will be constantly closed, or energized.

Referring in detail to the drawings, my inven tion is shown as being mounted on any suitable frame |0 having a transverse member II and a front plate l2. Mounted on the transverse member H in any suitable manner, as by means of the bolt-like members l3 and spacing sleeves I4, is a motor operating at constant speed, preferably, an alternating current synchronous induction motor |5. A reduction gearing l6 may be provided for driving the shaft I! at a desired number of revolutions per minute, said shaft I! having a collar l8 fixed thereto, which is provided with a driving pin I9.

A rotatable shaft-like'member is mounted on the wall |2 for rotation in a bearing provided thereon and extends through an opening in the wall l2, the same being manually rotatable in a manner to be described below. A long socket or bearing opening 22 is provided in the member 20, which receives the integral shaft portion 23 on the cam 24, which has an opening 25 therein, into which the driving'pin l9 extends. Thus the cam 24 is rotated about the axis of the shaft l1 and, also, of course, about the axis of the shaft 23 and the axis of the rotatable shaft-like member 20. The cam 24 is provided with a high portion 26 and a low portion 21, there being slightly inclined shoulders 28 and 29 at the junction of the cam portions 26 and 21, said cam rotating in the direction of the arrows in Figs 5, 6 and '7.

Cooperating with said cam 24 is shown a pair of switches 30 and 3|. Said switches are of a type that move from one alternative position to the outer alternative position thereof with a snap action by a minimum amount of movement of an operating member for the switch, such as the type of switch shown in the patent to Phillip K. McGall 1,960,020, patented May 22, 1934, the operating members for the switches comprising the arms 32 and 33 extending therefrom, said operating members 32 and 33 moving the movable elements of the switches indicated in the circuit diagram shown in Fig. 3 by the numerals 34 and 35, from contact with one stationary contact 36 to contact with another stationary contact 31, in the case of the movable contact element 34, and from a position in engagement with one stationary contact element 38 to a position in engagement with another stationary contact element 39, in the case of the movable contact element 35. the switches 33 and 3| being thus identical in construction and in operation so that a movement of the operating member 32 from one predetermined position to another predetermined position will have the same efiect in moving the movable contact element 34 of the switch 30 from one alternative position to another, as will such a movement of the operating member 33 on the movable contact element 35 of the switch 3|. The operating member 32 is provided with a projection 40 thereon engaging the surface of the cam 24 and the operating member 33 is provided with a similar projection 4| thereon, engaging the surface of said cam element 24, the projections 40 and 4| being of a character that the same will present a narrow edge to the surface of the cam, as will be obvious from Fig. 5.

The shaft-like member 20 is provided with an enlarged hub portion 42 at one end thereof, which is integral therewith, and a bearing member 43'is fixed, as by solder 2|, to the rear face of the front plate |2 of the frame l0 having a long bearing opening therein, so as to provide for accurate co-axial rotation of the member 20 about the axis of the shaft l1 and accurate coaxial rotation of the cam 24 about the axis of said shaft Said hub portion is provided with an arm 44, preferably, integral therewith,

projecting radially therefrom, which arm is of a fiat plate-like character and of any desired shape to provide a secure mounting for the switch member 30, which is mounted in fixed position on said arm 44 by means of the securing elements 45.

It will be obvious that as the arm 44 is rotated about the axis of the shaft-like member 20, and thus about the axis of rotation of the cam 24. the edge of the projection 40 in engagement with the cam will move to various positions relative to the projection 4| about the axis of rotation of the cam 24, so that either the high portion 25 or the low portion 21 of the cam will be engaged by said projections 40 and 4| at the same time or at different times, or will both be in engagement with the same portions of the cam for different time intervals. The cam is set screw I 8 or an'ysimil'ar means.

so made that the high portion 26 thereof and the low portion 21 thereof are of substantially equal length, each occupying 180' of the cam surface; except for the slightly inclined connetting portions 28 and 29. The inclination of "the portions 28 and 2'9is only such that the prosections will ride up the ame without catching on the ofis'e'ts in the cam thus provided, and Will not'dropviolently Olfll'fO the surface f the cam hom the high portion to the low portion there- 'of the movable switch member 31] may be provia-ed, comprising means for rotating the shaftlike member 20 about its aids. A simple form of such adjusting means comprises a disk-like dial member 16, which may be'provide'd with graduations l1 thereon,- for indicating the position that the member it assumes, the gradua- 'tions shown being. such as to divide an arc of "130* on the disk 46 into one hundred parts, so

as to each indicate one percent of the total rotation of the arc of 180", only some of the graduations being shown in the drawings for the sake of clearness; The disk-like member IS'is fixed to the shaft-like member 20 by means of a An arrow or "similar mark 51] serving as an indicator cooperating with the markings on the disk-like member may be prov'idec'l on the front plate l2.

"*Ihe means for rotating the disk-like member 46,

preferably, comprises a knob 51 integral with the disk-like member '46.

While the cam is described as having high and low portions covering an arc of substantially 180 and the scale is described as being graduated 'over an arc of 180", obviously by the use of a plurality of pairs of switches and shorter arcs, similar results can be obtained. Of course, the longer the arc through which the adjustment of the movable switch is made, the finer the adiustment'can be made on the scale pmvided,

by the ordinary operator of the device.

A cord 59 may be connected with any suitable electric outlet for connecting the timing device with a supply circuit, which would, of course, have to be an alternating current supply, if an alternating current motor of the character described is utilized. Said cord "is provided with conductors 60 and BI, which constitute the line wires, and any suitable switch 62 having an o erating member 63 may be provided in one of the line wires for throwing my timing device into and out of operation, the switch establishing connection between the terminal 64 and the terminal 6'5, thus connecting the one line conduotor 6| with the conductor 66 leading to one terminal of the motor I5, the other terminal of the motor being connected directly with the line wire 60. The switch 62 is not included in the circuit diagram in Fig. 3, as it is not of importance to the operation of the device. -61 extends from the device to the controlled circuit, containing the conductors 68 and 69 leading to said controlled circuit, the conductor 68 being connected directly with the conductor '60, being shown as being connected to the same terminal of the motor to which the conductor B0 is connected. it conductor 10 extends from the terminal 65, and thus from the line wire 6| to the movable contact element 34 of the switch 30,

A cord and the conductor is extends from the movable contact element 35 of the switch 3|.

The switch 3i is mounted in fixed position the front plate I 2 of the frame 10 by any suitable means, as by means of a bracket H secured to said plate 12 by means of securing elements 1 2,. the switch 3| being secured to the bracket by means of the securing elements 13 in a well known manner. A conductor 14 extends from the stationary contact 31 of the switch to the stationary contact 38 of the switch 31, and a conductor 15 extends from the stationar contact 36 of the switch 30 to the stationary contact 3 9 of the switch 3|. Assuming that the movable contact elements 34 and will be in the position shown in Fig. 3 when the projections and 4| on the operating members 32 and 33 are on the high portion 26 of the cam, it will be obvious that the controlled circuit, indicated generally by the numeral 16, will be disconnected from the line wires 69 and BI. However, should the operating member 32 drop off the high portion of the cam 26 onto the low portion 27 thereof while the operating member 33 is still on the high portion of the cam, the movable contact member 34 will then be instantaneousl'y moved from engagement with the stationary contact 36 to engagement with the stationary contact 37 and the circuit from the line to the controlled circuit 76 will be completed. the movement being substantially instantaneous due to the snap action characteristics of the movable switching elements 34 and 35. same result would occur if the operating member 33 descended to the low portion 2! of the cam 24 while the operating member 32 were still in engagement with the high portion 25 of the cam, as then the contact member 34 would remain in the position shown in Fig. 3, but the contact member 35 would move into engagement with the stationary contact member 39 to complete the circuit through the pair of switches. 'A similar movement in the opposite direction would take place whenever an operating member moved due to traveling from the low portion. 2''! of the cam to the high portion 26 thereof.

It will accordingly be obvious that if the projections M and 4] of the operating members are in engagement with the same portion of the cam th controlled circuit will b disconnected from the line wires, and that when said projections 40 and "4| are in engagement with difie'rent portions of the cam, that is, one with the high portion and the other with the low portion thereof, the circuit will be completed between the line wires and El and the controlled circuit 15. It will also be obvious that the length of time that the circuit will be either completed or not completed between the line wires and the controlled circuit will depend upon the relative position of the projecti'ons It and H on the operating members 32 and 33. shown in Fig. 6, in which the projections 10 and 4'! are aligned with each other transversely of cam, exactly the same portions of the cam will be engaged at all times by said projections as said cam rotates, and the change in position of the operating members 32 and 33, due to their travel from the high to the low portion of the cam, and viceversa, will take place simultane ously, and thus the circuit between the conductors 69 and In will be constantly open and the controlled circuit will be constantly disconnected from the line wires and will thus be continuously out of operation.

The

Thus when these are in the position However, when the adjustable switch member 30 is moved to the position shown in Fig. 7 the projection 40 thereon will always be diametrically opposite the projection 4| on the operating member 33, and thus said projection 40 will always engage the low portion 21 of the cam during the interval that the projection 41 engages the high portion 26 of the cam, and vice versa, the change from the one portion of the cam to the other at a distance of 180 from each other taking place simultaneously for the two operating members 32 and 33, and these will thus be always in relatively opposite positions, maintaining the movable contact elements 34 and 35 always in opposite positions, and thus keeping the conductors 69 and T constantly connected with each other and the controlled circuit 16 constantly connected with the line wires and thus constantly in operation.

It will be obvious that any position of the switch member 30 between the two extreme positions shown in Figs. 6 and 7 will cause the circuit between the conductor 69 and the conductor to be open and closed different intervals of time and the length of time that the circuit will be closed will decrease constantly as the projection 40 on the operating member 32 approaches the projection 4| on the operating member 33 as said switch member 30 is rotated by rotation of the arm 34 by means of the knob 54, and that the proportion of any entire time interval that the circuit is closed, down to the time required for one revolution of the cam 24 will be in direct proportion to the arcuate movement of the arm 44 from the position in which the operating member is shown in Fig. 6 to that shown in Fig. '7.

What I claim is:

1. The combination with a pair of switches each having a movable contact member, a switch operating member on each switch, and means for constantly determining the simultaneous position of said movable contact members, comprising a shaft, cam means fixed on said shaft, said cam means having high and low portions, means for rotating said shaft at a substantially constant speed, means on said operating members continuously engaging said cam means, and rotatable means for adjusting the position of one of said switches, about the axis of rotation of said shaft relative to the other thereof, to hold the operating member thereof in a position corresponding to that of the operating member of the other switch through from zero to one hundred percent of each revolution of said shaft, said rotary means for adjusting the position of one of said switches being connected to a dial with means thereon indicating its position and means for moving said dial.

2. In a device of the character described, a plurality of switches each comprising a pair of stationary contact members and a movable contact member movable back and forth between two alternative positions with said movable contact member in engagement with one of said stationary contact members in one of said positions and with the other of said stationary contact members in the other of said positions, a shaft, cam means fixed thereto having high and low portions each of uniform height, throughout the length thereof and each of substantially equal length, means for continuously rotating said shaft at a determined speed, a switch operating member on each switch the position of which determines the position of the movable contact member of said switch, said operating members each continuously engaging said cam means to each occupy two alternative positions, for intervals of equal length while alternately engaging said high and low cam portions to move the movable contact member it operates from engagement with one of said stationary contacts and into engagement with the other thereof upon engage'ment with one of said cam portions and out of engagement with said other stationary contact and into engagement with said one stationary contact upon engagement with the other of said cam portions, and means for adjusting the position of said switches relatively through an are substantially equal to that through which each of said cam portions extends to hold the operating members thereof in a corresponding position through from zero to one hundred percent of each revolution of said shaft.

3. The combination with a pair of switches each comprising a pair of stationary contact members and a movable contact member movable alternately into engagement with said stationary contact members, a switch operating member on each switch the position of which determines the position of the movable contact member of said switch, and means for constantly determining the simultaneous position of said movable contact members, comprising cam means having high and low portions of uniform height throughout their length, each of said cam portions having a length of substantially means for rotating said cam means at a substantially constant speed comprising a shaft fixed thereto, means on said operating members continuously engaging said cam means, and rotatable means for adjusting the position of one of said switches about the axis of rotation of said cam means relative to the other thereof through an arc of substantially 180, to hold the operating member thereof in a position corresponding to that of the operating member of said other switch through from zero to one hundred percent of each revolution of said shaft.

4. In a device of the character described, a plurality of switches each comprising a pair of stationary contact members and a movable contact member movable back and forth between two alternative positions with said movable contact member in engagement with one of said stationary contact members in one of said positions and with the other of said stationary contact members in the other of said positions, a shaft, cam means fixed thereto having high and low portions each of uniform height, throughout the length thereof and each of substantially equal length, means for continuously rotating said shaft at a determined speed, a switch operating member on each switch the position of which determines the position of the movable contact member of said switch, said operating members each continuously engaging said cam means to each occupy two alternative positions, for intervals of equal length while alternately engaging said high and low cam portions to move the movable contact member it operates from engagement with one of said stationary contacts and into engagement with the other thereof upon engagement with one of said cam portions and out of engagement with said other stationary contact and into engagement with said one stationary contact upon engagement with the other of said cam portions, and means for adjusting the position of said switches relatively through an are substantially equal to that through which each of said cam portions extends to hold the operating members thereof in a corresponding position through from zero to one hundred percent of each revolution of said shaft, said adjusting means having means for indicating the adjustment thereof.

5. The combination with a pair of switches each comprising a pair of stationary contact members and a movable contact member movable alternately into engagement with said stationary contact members, a switch operating member on each switch the position of which determines the position of the movable contact member of said switch, and means'for constantly determining the simultaneous position of said movable contact members, comprising cam means having high and low portions of uniform height throughout their length, each of said cam portions having a length of substantially 180, means for rotating said cam means at a substantially constant speed comprising a shaft fixed thereto, means on said operating members continuously engaging said cam means, and rotatable means for adjusting the position of one of said switches about the axis of rotation of said cam means relative to the other thereof through an arc of substantially 180, to hold the operating member thereof in a position corresponding to that of the operating member of said other switch through from zero to one hundred percent of each revolution of said shaft, said adjusting means having means for indicating the adjustment thereof.

6. In a device of the character described, a pair of switches each having a pair of stationary contacts and a movable contact member movable back and forth between two alternative positions with said movable contact member in engagement with one of said stationary contacts in one of said positions and with the other of said contacts in the other of said positions, a shaft, cam

' means coaxially fixed on-said shaft having high and low portions each of substantially uniform height and each of equal length, means for rotating said shaft at a substantially constant speed, a movable switch operating member on each switch the position of which determines the position of the movable contact member of said switch, said operating members engaging said cam means, one of said switches being mounted in fixed position with its operating member occupying a fixed station in the path of movement of said cam means, a member mounted for rotation about the axis of said shaft, an arm of fixed length extending therefrom, the other of said switches being mounted on said arm for movement therewith in an arcuate path about the axis of rotation of said shaft to adjust the station of its operating member in the path of movement of said cam means through an arc substantially equal to that through which each of said cam portions extends, means for rotating said member carryingsaid arm through an arc substantially the length of each of said cam portions, and means rotatable with said last mentioned member for indicating the adjustment of the position of said station.

7. In a device of the character described, a pair of identical switches each comprising a pair of stationary contacts and a movable contact member movable back and forth between two alternative positions, with said movable contact member in engagement with one of said stationary contacts in one position thereof and with thev other stationary contact in the other position thereof, the stationary contacts of one switch being electrically connected each with one of the stationary contacts of the other switch to connect said movable contact members of said pair of switches in series in one relative position thereof and disconnect said movable contact members from each other in the other relative position thereof, a shaft, cam means fixed coaxially on said shaft, having high and low portions each of substantially uniform height, and each extending around substantially of the face of said cam means, means for continuously rotating said shaft at a determined speed, a movable switch operating member on each switch the position of which determines the position of the movable contact member of that switch, said operating members continuously engaging said cam means, and means for adjusting the position of one 'of said switches relative to the other thereof about the axis of rotation of said cam through an arc of substantially 180 to adjust the position of the operating member thereof about the axis of said cam means to any position between one in which said movable contact members are continuously connected in series to one in which the same are continuously disconnected.

PAUL A. COFFIVIAN', JR. 

